Red Sox pitcher Jon Lester's cutter has a lot to do with his success this season.
The cutter was Lester's best offering back in his prime, and it's jumped back to those levels after falling off in recent seasons. Lester's whiff rate on his cutter has jumped to 15.85 percent this year, which is where it sat from 2009 to 2011. The past two seasons, Lester averaged a 12 percent whiff rate with the pitch.
The resurgence of his cutter has helped Lester strike out 66 batters in just 55 2/3 innings thus far. Even if that rate doesn't hold up, it's starting to look like his strikeout rate will return to pre-2012 levels. His surprising early season performance seems sustainable.